Study On Earth-Rock Allocation Scheme Of Lianghekou High Gravelly Earth-Core Rockfill Dam

In the dam filling construction of high core rockfill dam(HCRFD),the construction period is long,the work quantity is large,there are many working procedures,and it is quite easily affected by raining conditions.Therefore,in the construction process of dam body filling how to make the reasonable earthwork allocation planning has always been the focus of research on dam construction.Lianghekou Hydropower Station is located on the main stream of Yalong River in Yajiang County,Ganzi Tibetan Autonomous Prefecture,Sichuan Province,China.Its water retaining structure is the core rockfill dam with the maximum dam height of 295m.The total filling volume of the dam body is about 41,000,0008)~3.Restricted by factors such as terrain of dam site area,construction site,farmland resources and reservoir filling,the earthwork allocation system has a complicated structure and many influencing factors,and is randomly and uncertain。According to the characteristics such as many kinds of filling materials in the dam body,a large filling quantity,high allocation strength,complicated transportation system,special dam material gradation and being easily affected by precipitation,this paper analyzes the earthwork allocation system of Lianghekou HCRFD,builds the model of the dam body through the arrangement plan of dam structure of Lianghekou Hydropower Station,obtains the filling quantity of each filling layer,establishes the whole-process and dynamic earthwork allocation model based on the simulation of the filling process of the dam body,simulates the transportation process of the filling material of the dam body and the filling progress of the filling layer of the dam body,and provides basis for the optimization of the earthquake allocation scheme.Main content and results of the research work are as follows:1)The model of the dam body of Lianghekou Hydropower Station is established.According to the structural layout plan of the dam of Lianghekou Hydropower Station,the model of the dam body is established,and the work quantity of the filling layer of the dam body is obtained according to the thickness of the filling layer in each area of the dam body.2)The precipitation process in the dam site area is predicted.With the data of precipitation of the previous years in the dam site area as the learning sample,the BP neural network algorithm is used to obtain the predicted data of precipitation process in the construction process of the dam body filling in the dam site area.3)The transportation planning of the filling material of the dam body is analyzed.Based on the transportation road layout of excavation area,stock ground,blending site,transit depot,slag yard and filing material of dam body,combined with the transportation process of different filling materials,the filling elevation and use period of each filling road are obtained by analysis.4)The filling progress simulation model of the filling layer of the dam body is established.The basic principle of the discrete event simulation system is used to establish the filling progress simulation model of the filling layer of the dam body.With precipitation and filling elevation in the adjacent area as the constraint condition,the starting and ending elevation of the filling layers in different areas,filling volume,accumulative volume,and the starting and ending time of filling are obtained.5)The earthwork allocation model based on the filling progress simulation of the dam body is established.According to the simulation results of the filling progress of the dam body,the reasonable demands are proposed for the exploitation of the stock ground,the material supply of each stock ground is defined,the filling material source and work quantity of exploitation are obtained,and it provides basis for the optimization of earthwork allocation scheme.